The present invention relates to metal-oxide-semiconductor field-effect transistors (MOSFET), and more specifically, to gate contacts in MOSFETs.
The MOSFET is a transistor used for amplifying or switching electronic signals. The MOSFET has a source, a drain, and a metal oxide gate electrode. The metal gate is electrically insulated from the main semiconductor n-channel or p-channel by a layer of insulating material, for example, silicon dioxide or glass, which makes the input resistance of the MOSFET relatively high. The gate voltage controls whether the path from drain to source is an open circuit (“off”) or a resistive path (“on”).
Generally, the gate contact (also called the CB) is formed over shallow trench isolation (STI) regions to avoid shorting between the gate contact and the source/drain contact (also called the TS). However, placing the gate contact over the active area (also called the RX), or the semiconductor regions where the source/drain regions are formed, may be beneficial for increasing the integration density and reduce device scaling.